The most suitable and most widely used materials for casings of electric fuses are ceramic materials and synthetic-glass-cloth laminates. If one chooses a ceramic material, one foregoes all of the many significant advantages offered for the particular purpose by synthetic-resin-glass-cloth laminates, and vice versa.
It is one of the objects of the invention to provide electric fuses having casings of synthetic-glass-cloth laminates which have desirable features which were, heretofore, only found in fuses having casings of a ceramic material.
Another object of the invention is to provide fuses the casings of which have portions which are of a pultruded tubing material of uniform wall thickness that is reinforced by a squirrel-cage-like structure surrounding the same, which fuses can be manufactured at moderate cost.
Other objects and advantages of the invention will become more apparent from what follows.